Display devices such as liquid crystal display elements have features that include compact size (small size), slimness (small thickness), low power consumption and lightness (light weight). Because of this, currently, the display devices are extensively used for various electronic equipments. Drive circuits or thin film transistors for driving these display devices have been manufactured using an exposure apparatus generally referred to as a stepper.
However, the size of liquid crystal display elements, in particular, is becoming ever larger, and after the 8th generation, there occur many difficult problems, such as manufacturing costs and device transporting limitations, which cannot be solved by the scale-up extension of conventional technology. Further, in order to reduce the manufacturing costs, in addition to improving efficiency by increasing the substrate size, reduction in apparatus costs, reduction in running costs and improvement of a yield of a large-sized panel have become key points.
In addition, organic ELs, field emission displays and the like have been launched in the market, and reduction in an apparatus cost and reduction in a running cost have also become significant problems to be solved in relation to the manufacturing of next generation of those display devices.
Patent Document 1 discloses a method for manufacturing liquid crystal display elements using a flexible substrate which is in a roll shape as a countermeasure for the reduction of an apparatus cost of the liquid crystal display elements and the reduction of a running cost.
Patent Document 2 discloses a display defect detection method for detecting defects by selecting a resolution from an image of a liquid crystal panel, which is photographed with high accuracy by using a line sensor, according to the type of various display defects such as rubbing unevenness (ununiformity) or gap unevenness (ununiformity).    [Patent Citation 1] Japanese Patent No. 3698749    [Patent Citation 2] Japanese Patent Publication No. 2004-279239
The roll shaped flexible substrate has a length between several tens of meters and several hundreds of meters, as disclosed in the examples of Patent document 1. Therefore, it is necessary to stop a manufacturing line when a fatal defect is generated. Meanwhile, there also exist defective portions which can be simply repaired.
Patent Document 2 selects an image resolution according to the type of display defects in finished products (end-products) of liquid crystal display elements, but its purpose is only to find defects. Thus, whether or not the defects must be repaired is not determined.